ceph/src/arrow/java/dataset/src/main/java/org/apache/arrow/dataset/jni/NativeDataset.java

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one or more
   3  * contributor license agreements.  See the NOTICE file distributed with
   4  * this work for additional information regarding copyright ownership.
   5  * The ASF licenses this file to You under the Apache License, Version 2.0
   6  * (the "License"); you may not use this file except in compliance with
   7  * the License.  You may obtain a copy of the License at
   8  *
   9  *    http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 package org.apache.arrow.dataset.jni;
  19
  20 import org.apache.arrow.dataset.scanner.ScanOptions;
  21 import org.apache.arrow.dataset.source.Dataset;
  22
  23 /**
  24  * Native implementation of {@link Dataset}.
  25  */
  26 public class NativeDataset implements Dataset {
  27
  28   private final NativeContext context;
  29   private final long datasetId;
  30
  31   private boolean closed = false;
  32
  33   public NativeDataset(NativeContext context, long datasetId) {
  34     this.context = context;
  35     this.datasetId = datasetId;
  36   }
  37
  38   @Override
  39   public synchronized NativeScanner newScan(ScanOptions options) {
  40     if (closed) {
  41       throw new NativeInstanceReleasedException();
  42     }
  43     long scannerId = JniWrapper.get().createScanner(datasetId, options.getColumns().orElse(null),
  44         options.getBatchSize(), context.getMemoryPool().getNativeInstanceId());
  45     return new NativeScanner(context, scannerId);
  46   }
  47
  48   @Override
  49   public synchronized void close() {
  50     if (closed) {
  51       return;
  52     }
  53     closed = true;
  54     JniWrapper.get().closeDataset(datasetId);
  55   }
  56 }